Cutting apparatus



Dec. 8, 1942. w. w. .BROUGHTON CUTTING APPARATUS Filed Dec. 3, 1940 2Shee ts-Sheet' 1 INVENTOR MM. BROUGHTON 331 VIM-14M.

ATTORNEY 1942- w. w. BROUGHTON 2,304,238

CUTTING APPARATUS Filed Dec. 3, 1940 2 Sheets-Sheet 2 34 I A 55 L 5 5276 130 4/ 60 url" 29 6/ I 30 i l 28 5/ FIG. 7 Fl 6. 8

" L INVEN TOR mm EROUGHTON BY 97 s s 2 ATTORNEY Patented Dec. 8, 1942CUTTING APPARATUS William W. Broughton, New Brighton, Staten Island, N.Y., assignor to Bell Telephone Laboratories, Incorporated, New York, N.Y., a. corporation of New York Application December 3, 1940, Serial No.368,349

Claims. (01. 125-13) This invention relates to cutting apparatus, andmore particularly to apparatus for sawing quartz crystals.

Quartz crystal plates are used, for example, in filters in thecommunications art and these plates are produced from quartz crystalblanks. Due to the brittle nature, the granular structure and thenatural hardness of quartz crystals, the production of plates ofdefinite and uniform thickness therefrom is quite difiicult andpainstaking. The crystal plates cut from the crystal blanks must be cutwith the grain of the blank and when the plates are rather thindifficulties arise in avoiding breaking of the plates before the cut iscompleted.

An object of the invention is to provide a. cutting apparatus which isparticularly adapted for efficiently and accurately cutting plates fromquartz crystal blanks.

With this and other objects in view, the invention comprises a cuttingapparatus includ-.

ing a work or quartz crystal support which, in addition to being mountedfor movement into selected variable angles relative to a driven cuttingelement, is mounted for arcuate movement to feed the work to the elementand for simultaneous oscillatory movement during the cutting operationto cause substantially tangential contact between the element and thework.

Other objects and advantages will be apparent from the followingdetailed descriptionwhen taken in conjunction with the accompanyingdrawings, wherein Fig. l is a side elevational View of the cuttingapparatus, portions thereof being broken away;

Fig. 2 is a front elevational view of the cutting apparatus, a portionthereof being shown in section;

Fig. 3 is 'an enlarged fragmentary detailed view of the work support andthe immediate structure associated therewith;

Fig. 4 is a fragmentary side elevational view of the structure shown inFig. 3, portions thereof being shown in section;

Fig. 5 is a fragmentary sectional view taken along the line 5-5 of Fig.3;

Fig. 6 is a diagrammatic illustration of the fluid means to impart oneof the movements to the work support;

Fig. 7 illustrates the relative positions of the work and the cuttingelement at one end of one Fig. 9 illustrates the work at the completionof a cutting operation.

Referring now to the drawings, attention is first directed to Figs. 1and 2, wherein atable ID is supported by vertical leg members ll havingreenforcing cross pieces l2. Substantially U- shaped bearing supports l3are positioned with the upper leg portions thereof resting upon thecross pieces l2 in general alignment with each other, while the lowerleg portions support bearings iii. The U-shaped members are of sturdystructure, they being formed of suitable mate rial such as channel ironand 'seoured in place upon the cross pieces by suitable meanssuch aswelding. The bearings l5 receive stub shafts I! which cooperate with thebearings in providing a pivotal support for a work supporting frameindicated generally at I8. The frame l8 has two main members I9 and 20joined by an intermediate member 2| to complete a rigid structure. Themembers l9 and 20 are of channel structure, supporting the stub shaftsI1 at the lower ends thereof, their upper ends being spaced apart asillustrated in Fig. 2 and formed as illustrated in Figs. 1 and 4.

Adjacent the upper ends of the members l9 and 20 of the frame l8 amovable support 25 (Figs. 1 to 5 inclusive) is disposed. This movablesupport is in the form of a flat plate having two arcuate tracks 28 and29 secured to or formed integral therewith, the arcuate contours of thetracks having radii from a common center and each track having a groovetherein. The groove for the track 28 bears reference numeral 30 and ison the under side of thetrack, while the groove for the track 29 bearsreference numeral 3! and is on the upper or inner side of the track.

The movable support 25 is supported by the frame I8 at'fourspaced'points represented by a pair of bolts 33 in the lower portionthereof and a pair of bolts 34 in the upper portion thereof. The bolts33, as illustrated in Fig. 4, ex-

tend through .the' support 25 and through an.

aperture in a wall of each of the members l9 and 20 of the frame 3. Theapertures through which the bolts pass are of sufficient size' to permitmovement of the support 25 'arcuately about the ends of the bolts 34,but the support is normally held in the position shown in Fig. 4 bysprings 36 positioned between the walls of their respective framemembers ISVand 2|] and the adjacent heads of the'bolts 33. The bolts 34are slightly different in structure from the bolts 33, in that the heads38 thereof are of the fiat tapered type and are disposed in apertures ofsimilar contour in the movable support 25. Semi-cylindrical members 40are positioned between the movable support and the adjacent flatsurfaces of their respective frame members I9 and 20, the fiat surfacesof the members lying flush with the adjacent wall of the movable supportwhile the arcuate surfaces engage and are positioned to ride upon theirrespective frame members. Tapered opening M are pro-. vided in thesemi-cylindrical members which hereinafter may be termed pivot members,these openings allowing movement of the members relative to their bolts34. The bolts 34- extend through apertures 43'. in embossed. portions ofthe frame members I9 and 20 as illustrated in Fig. 4.

A work supporting table 4.4 has table supporting means, indicatedgenerally at 45, for adjustably securing the table to the movablesupport .2.

2.5. The table supportingmeans includes an element 46 formed, forexample,.of sheet metal with a. flat upper edge and a substantiallyarcuate lower edge. The element. 46 has an arcuate tongue portion 41 ofa cross-sectional contour, as

illustrated in Fig. 4, to interengage the track 29 for movement in anarcuate path on the track. Locking means in the form of a bolt 48disposed in an aperture in the lower central portion of the arcuateelement 46, has a nut 49 formed to interengage the groove 30 of thetrack 28, to lock the element in any desired position relative tothe-movable support 25. The" outer ends of the element 46 are bentoutwardly, as at 50' and 5! (Figs. 3 and 5-), to support a pair ofspaced rods 52 and an adjusting screw 53-. A illustrated in Fig. 5, therods 52 are held against displacement by collars 54' disposed on theends thereof, while the adjusting screw is provided with a hand wheel 55and is held. against longitudinal move-- ment relative to the rods-bysuitable means such as collars 56.

A cubical member 69 is apertured at M to receive the rods 52, andat- 62to receive the adjusting screw 53. Slots 63 are formed in the member atthe apertures 6!; to form resilient portions so that the. member 60. maybe held against accidental displacement. A vertical aperture is formedin thev central portion of the member 60 to receivea nut 66 which isthreaded to receive the adjusting screw 53 and tocause movement. of themember 60. ontherods 52 upon rotation of the adjusting screw. A coverI9, which in the present instancev is formed of sheet metal, has sideand. end portions. bent downwardly, the side portions being positionedupon each. side of the member 60 and resting upon integral projectionsor shoulders H of the mem her. while the end portions extend upon theoutside-surfaces of the ends 50 and 5! of the element 4.6 (Fig. 5).where. apertures. are provided for the rods 52 and the adjusting screw53.

The member 60. supports a bracket. 15 through the aid. of screws 16,.the latter extending through legs. I! of the bracket and intov theprojections II of. the. member. The legs I1 of the bracket straddle themember 60 and the cover I0 positioned thereon, so that the bracket. maymove freely with the member 60. through. the adjusting. of the screw53.. A plate I8 fixed to the bracket I5 rides on the flat upper surface.of the element 46 during movement of the table 44 and the partslinkingthe table with the adjusting. screw 53.. A central aperture 82 in thebracketv I5 receives a column 83 of. the. work supporting justment ofthe screw 53.

table 44, the column being secured in place by a set screw 84.

Thework supporting table 44 may be adjusted arcuately through theadjustment of the element 46 relative to the movable support 45, toposition work thereon at any desired angular position with respect to acutting element shown in Figs. 1 and 2, and the work may be moved whilein the selected angular position through the ad- Two other movements,which have not as yet been described, may be imparted to the worksupport, one being the movement of the work support in another acuatepath to feed work to the cutting element and the other being means tooscillate the table during the cutting operation to cause point contactbetween the cutting element and the work. The first of these movingmeans includes a cylinder 92 including a piston (not shown) fixed to apiston rod 93. The outer end of the piston rod 93 is adjustablyconnected through a link 94 to the cross member 2i of the frame I8. Thecylinder 92 is supported by bracket 95 at the under side of the tableI0, each end of the cylinder communicating with the fiuid lines 96 and91 of a fluid supply circuit shown in Fig. 6. The fluid lines 96 and 9'!are supplied with fluid under pressure by a reversible constant deliverypump 98, a pressure gage being indicated. at 99, to determine thepressure supplied to the piston in the cylinder. A relief valve I00. isdisposed in a by-pass IOI between the fluid lines 96 and. 91 and has avalve stem I02 extending downwardly therefrom urged my this direction bya spring I03 which normally seats the. valve. Pressure against thepiston in the cylinder 92 will. force theframe I8 clockwise (Fig. 1)aboutv it spivots IT... This movement i controlled, however, through alever I05 having one end engaging the-valve stem. I02 and pivoted at I06to a bracket supported by the table W. A plurality of apertures. I0] isprovided in the other end of the lever I05. and to any one of these anadjustable link. I09 is connected, the link [09 being oscillated.through an. eccentric I09 to which it is connected. The eccentric. I09isv driven by av motor IIO through a pulley III, a belt II2, a pulleyH3. and reduction gears indicated generally at I I 4, the latterdriving. a shaft II5 uponwhich eccentric I09 is mounted. The eccentricI09. is also grooved to receive a belt II6 which, through a pulleyI.I'I, drives a shaft IIB of the pump 98 shown schematically in Fig- 6.

The means for oscillating the work support includes an arm I20 havingone end fixed to: the movable support 25 and operatively connected,intermediate. its ends, to. one end of a link I2I. A. bearing I22 isfixed to the. other end, of the link I2I and is disposed on a pin I23,the. latter carried. by a slide I24 and having a nut I25- on the outerthreaded end thereof. The slide is slidably adjustable in a groove I26of an eccentric I21 and, held in adjusted position by the nut. I25. Theeccentric is mounted on. the end of. the. shaft I I 5 opposite the endsupporting the. eccentric. I09.

The cutt-ing element. 90 is circular and of. the type employed incutting stones and the. like. A motor I25 mounted upon a bracket I26 on.the table I0, rotatesthe cutting element when energized.

Upon conditioning the apparatus for operation the work is. disposed uponthe work. support or table 44. In the present instance a. quartz crystalblank I33 is disposed upon the. work support and secured thereto bycement I.3.I (Fi s. 3 and 4) or other suitable means.

Before the quartzcrystal blank is'mounted This adjustment is made byloosening the riding in groove 3i of the track 29 until the support ofthe crystal blank has been located in the desired position. Bolt is thentightened to lock the element 45 in the adjusted position.

The work support M'may then be moved lat- Jerally relative to thecutting element to position the crystal blank for the first cutting.

This movement of the work support is brought about by rotation of theadjusting screw 53 to move the cubical member 68 with its associatedparts, including the bracket 15 and the work support 44,

longitudinally on the spaced rods 52. When these two adjustments havebeen made, the adjustment of the work support to locate the crystalblank with the grain thereof parallel with the cutting element and theadjustment of the work support to position the crystal blank for thefirst cut, the apparatus is in condition for operation. The motor I25 isthen energized and at the same time the motor HE! is energized, thefirst motor driving the cutting element While the second motor drivesthe mechanism for imparting the two movements to the work support, oneto feed the crystal blank to the cutting element and the other to causesimultaneous oscillatory movement with the feeding movement to causetangential contact between the cutting element and the Work.

The two movements of the work support during the cutting operation arecontrolled through the eccentrics H19 and 21 which are mounted upon thecommon shaft H5. These eccentrics are synchronized so that, during onehalf of a' cycle of the eccentric l2! to cause the work sup port 44 tobe moved clockwise, the valve lfli! in the by-pass ID! of th fluidcontrol means (Fig.

6) is closed, allowing pressure from the pump 98 to move the piston inthe cylinder 92 and thus move the frame Iii with the work supportclockwise (Fig. 2). During the other half of the cycle of th eccentricsI09 and 52! the work support is rocked counterclockwise and during thismovement the valve lflfl is opened through the link I08 connecting thelever N35 with the eccentric 109. The opening of the valve I90 opens thebypass llll for the circulation of the fluid from the pump therethroughand equalizes the pressure on both sides of the piston in the cylinder,removing or rendering ineffective the force for moving the frame !8 andthe work support relative to the cutting element 90. In cutting quartzcrystals the maximum pressure which may be employed in feeding the workto the cutting element is approximately 8 pounds. Therefore, during therocking or oscillatory movements of the work relative to the cuttingelement, causing a cut in the work of an arc with a radius greater thanthat of the cutting element, the pressure ma be applied to the workduring the rocking or oscillatory movement in one direction, but thispressure must be removed during the rocking or oscillatory movement ofthe work in the opposite direction. This may be more clearly understoodby viewing Figs. 7 and 8. Considering Fig. 7, it will be noticed thatthe cutting element is rotating clockwise and that th work has reachedthe extreme point in its oscillatory movement counterclockwise, leavinga gap between thecut'and the edge of the cutting element from the bottomof the cut where'the work and the cutting element engage, to. the top ofthe cut. Let it be assumed now that during the continued rotation of'the cutting element clockwise, the work is moved arcuately clockwise tofeed the cut surface point' by point to the cutting element. During thishalf cycle of th arcuate movement of the work clockwise it may be saidthat the cutting element is cutting up-hill and into or against thedirection of movement of the work. Therefore, the movementof the workis. opposite that of the cutting element and during such opposedmovements a certain pressure will build up between the cutting elementand the work which "will be suflicient for this half cycle of thecutting operation without any added force through the feeding meansassociated withthe frame Hi. If the feeding means for the frame shouldbe rendered operative during thishalf cycle, that is, should the valveIfifi be closed to render the pump 98 effective to apply' a movingforce'to the frame, this force when coupled with the force created bythe Cutting'element cutting up hill or opposite the force or "directionof movement of the work, would cause th cutting element to become heatedand to break the work, thus rendering the device ineffective. The forcefor moving the fram with thework support and the work during this halfcycle is, thereforeynot needed. The back pressure built up during theclockwise opposing movements ofthe work relative to the cutting elementis sufficient during this half cycle.

During the next half cycle. of movement of the work support through themoving means coupled with the eccentric I21 to rock the work clockwise,the work would be moved away from the cutting element should thehydraulic frame moving means not be effective to apply th requiredpressure to keep the work in engagement with the cutting element. Duringthis half cycle the eccentric I09 is moved to move the lever I05 throughth link N18, to allow the spring I03 of the valve Hill to close thevalve, rendering the pump 98 effective to force the piston in thecylinder to the right (Fig. 1) and move the frame with the work supportand the work toward the cutting element. Therefore, during the lastmentioned cycle of the oscillating means, the Work is moved toward thecutting element through the movement of the frame 58 while the work isrocked or oscillated in a direction with the cutting element from theposition shown in Fig. 8 to the position shown in Fig. 7.

Due to the brittle nature of the crystal blank the cut does not extendall the way through the blank, as illustrated in Fig. 9. This leaves anuncut portion beginning at a thin edge, increasing in thickness to thecenter portion of the cut and terminating in a thin edge so that thepiece may be readily broken from the blank. This result is brought aboutthrough the arcuate movement of the work support with the frame l8 aboutits aligned pivots ll. This apparatus, therefore, provides a cuttingelement mounted at a position to rotate at a constant speed in onedirection. Positioned near the cutting element is a work support movablearcuately to locate work mounted thereon in any desired angular positionwith respect to the cutting element. Through the ad-.

justing screw 53 the work support may be moved to move the work from onecutting position to another after each cutting operation has beencompleted. Another means is associated with the work support tooscillate it arcuately, moving the work arcuately with respect to thecutting element in definite cycles synchronized with means to move theframe so that during one half of each cycle wherein the work support isoscillated, the moving means for the frame is operative to apply -adefinite pressure of the work on the cutting element, this means beingrendered inoperative during the other half of the oscillating cyclewherein the work is moved in a direction opposing that of the cuttingelement, rendering the cutting element effective to push the work in adirection away therefrom and build up a sufficient pressure for thecutting operation.

The embodiment of the invention herein disclosed is illustrative and maybe modified and departed from in many ways without departing from thespirit and scope of the invention as pointed out in and limited solelyby the appended claims.

What is claimed is:

1. In a cutting apparatus, a cutting element, means operable tooscillate work to be out toward and away from the cutting element, andfeeding means synchronized with the said oscillating means to create aforce to move work toward the cutting element during one oscillatorymovement of the work.

2. In a cutting apparatus, a cutting element, means operable tooscillate Work to be out toward and away from the cutting element, andfeeding means synchronized with the said oscillating means to create aforce to move work toward the cutting element during oscillatorymovement of the work away from the cutting element.

3. In a cutting apparatus, a cutting element, means operable tooscillate work to be out toward and away from the cutting element,feeding means synchronized with the said oscillating means to create aforce to move work toward the cutting element during oscillatorymovement of the work away from the cutting element, and means to renderthe feeding means ineifeetiv during oscillatory movement of the worktoward the cut;- ting element.

4. In a cutting apparatus, a rotatable cutting element, a support forwork to be cut, power means to move the support with the work in a pathrelative to the cutting element to render the element effective to cut agroove in the work, means to simultaneously therewith impart repeatedtransverse movements to the support and work, and means controlled bythe transverse moving means to render the said power means ineffectiveduring certain of the' transverse movements of the support and work.

5. In a cutting apparatus, a rotatable cutting element, a support forwork to be cut, power means to move the support with the work in a pathrelative to the cutting element to render the element effective to cut agroove in the work, means to simultaneously therewith impart repeatedtransverse movements to the support and work, and means controlled bythe transverse moving means to render the said power means ineffectiveto move the support and work during alternate transverse movementsthereof.

WILLIAM W. BROUGHION'.

